getnameinfo.c revision 1.14
1 /* $NetBSD: getnameinfo.c,v 1.14 2000/04/24 09:27:31 itojun Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * Issues to be discussed: 34 * - Thread safe-ness must be checked 35 * - Return values. There seems to be no standard for return value (RFC2553) 36 * but INRIA implementation returns EAI_xxx defined for getaddrinfo(). 37 * - RFC2553 says that we should raise error on short buffer. X/Open says 38 * we need to truncate the result. We obey RFC2553 (and X/Open should be 39 * modified). 40 */ 41 42 #include "namespace.h" 43 #include <sys/types.h> 44 #include <sys/socket.h> 45 #include <net/if.h> 46 #include <netinet/in.h> 47 #include <arpa/inet.h> 48 #include <arpa/nameser.h> 49 #include <netdb.h> 50 #include <resolv.h> 51 #include <string.h> 52 #include <stddef.h> 53 54 #ifdef __weak_alias 55 __weak_alias(getnameinfo,_getnameinfo) 56 #endif 57 58 #define SUCCESS 0 59 #define ANY 0 60 #define YES 1 61 #define NO 0 62 63 static struct afd { 64 int a_af; 65 int a_addrlen; 66 int a_socklen; 67 int a_off; 68 } afdl [] = { 69 #ifdef INET6 70 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 71 offsetof(struct sockaddr_in6, sin6_addr)}, 72 #endif 73 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 74 offsetof(struct sockaddr_in, sin_addr)}, 75 {0, 0, 0}, 76 }; 77 78 struct sockinet { 79 u_char si_len; 80 u_char si_family; 81 u_short si_port; 82 }; 83 84 #ifdef INET6 85 static char *ip6_sa2str __P((struct sockaddr_in6 *, char *, int)); 86 #endif 87 88 #define ENI_NOSOCKET 0 89 #define ENI_NOSERVNAME 1 90 #define ENI_NOHOSTNAME 2 91 #define ENI_MEMORY 3 92 #define ENI_SYSTEM 4 93 #define ENI_FAMILY 5 94 #define ENI_SALEN 6 95 96 int 97 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 98 const struct sockaddr *sa; 99 size_t salen; 100 char *host; 101 size_t hostlen; 102 char *serv; 103 size_t servlen; 104 int flags; 105 { 106 struct afd *afd; 107 struct servent *sp; 108 struct hostent *hp; 109 u_short port; 110 int family, i; 111 char *addr, *p; 112 u_int32_t v4a; 113 int h_error; 114 char numserv[512]; 115 char numaddr[512]; 116 117 if (sa == NULL) 118 return ENI_NOSOCKET; 119 120 #ifdef BSD4_4 121 if (sa->sa_len != salen) 122 return ENI_SALEN; 123 #endif 124 125 family = sa->sa_family; 126 for (i = 0; afdl[i].a_af; i++) 127 if (afdl[i].a_af == family) { 128 afd = &afdl[i]; 129 goto found; 130 } 131 return ENI_FAMILY; 132 133 found: 134 if (salen != afd->a_socklen) 135 return ENI_SALEN; 136 137 port = ((struct sockinet *)sa)->si_port; /* network byte order */ 138 addr = (char *)sa + afd->a_off; 139 140 if (serv == NULL || servlen == 0) { 141 /* 142 * do nothing in this case. 143 * in case you are wondering if "&&" is more correct than 144 * "||" here: RFC2553 says that serv == NULL OR servlen == 0 145 * means that the caller does not want the result. 146 */ 147 } else { 148 if (flags & NI_NUMERICSERV) 149 sp = NULL; 150 else { 151 sp = getservbyport(port, 152 (flags & NI_DGRAM) ? "udp" : "tcp"); 153 } 154 if (sp) { 155 if (strlen(sp->s_name) > servlen) 156 return ENI_MEMORY; 157 strcpy(serv, sp->s_name); 158 } else { 159 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 160 if (strlen(numserv) > servlen) 161 return ENI_MEMORY; 162 strcpy(serv, numserv); 163 } 164 } 165 166 switch (sa->sa_family) { 167 case AF_INET: 168 v4a = (u_int32_t) 169 ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr); 170 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 171 flags |= NI_NUMERICHOST; 172 v4a >>= IN_CLASSA_NSHIFT; 173 if (v4a == 0) 174 flags |= NI_NUMERICHOST; 175 break; 176 #ifdef INET6 177 case AF_INET6: 178 { 179 struct sockaddr_in6 *sin6; 180 sin6 = (struct sockaddr_in6 *)sa; 181 switch (sin6->sin6_addr.s6_addr[0]) { 182 case 0x00: 183 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 184 ; 185 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 186 ; 187 else 188 flags |= NI_NUMERICHOST; 189 break; 190 default: 191 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 192 flags |= NI_NUMERICHOST; 193 } 194 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 195 flags |= NI_NUMERICHOST; 196 break; 197 } 198 } 199 break; 200 #endif 201 } 202 if (host == NULL || hostlen == 0) { 203 /* 204 * do nothing in this case. 205 * in case you are wondering if "&&" is more correct than 206 * "||" here: RFC2553 says that host == NULL OR hostlen == 0 207 * means that the caller does not want the result. 208 */ 209 } else if (flags & NI_NUMERICHOST) { 210 int numaddrlen; 211 212 /* NUMERICHOST and NAMEREQD conflicts with each other */ 213 if (flags & NI_NAMEREQD) 214 return ENI_NOHOSTNAME; 215 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 216 == NULL) 217 return ENI_SYSTEM; 218 numaddrlen = strlen(numaddr); 219 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 220 return ENI_MEMORY; 221 strcpy(host, numaddr); 222 #if defined(INET6) && defined(NI_WITHSCOPEID) 223 if (afd->a_af == AF_INET6 && 224 (IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr) || 225 IN6_IS_ADDR_MULTICAST((struct in6_addr *)addr)) && 226 ((struct sockaddr_in6 *)sa)->sin6_scope_id) { 227 #ifndef ALWAYS_WITHSCOPE 228 if (flags & NI_WITHSCOPEID) 229 #endif /* !ALWAYS_WITHSCOPE */ 230 { 231 char scopebuf[MAXHOSTNAMELEN], *s; 232 int scopelen; 233 234 if ((s = ip6_sa2str((struct sockaddr_in6 *)sa, 235 scopebuf, 0)) == NULL) 236 /* XXX what should we do? */ 237 strcpy(scopebuf, "0"); 238 239 scopelen = strlen(scopebuf); 240 if (scopelen + 1 + numaddrlen + 1 > hostlen) 241 return ENI_MEMORY; 242 243 #if 0 244 /* 245 * construct <scopeid><delim><numeric-addr> 246 */ 247 /* 248 * Shift the host string to allocate 249 * space for the scope ID part. 250 */ 251 memmove(host + scopelen + 1, host, 252 numaddrlen); 253 /* copy the scope ID and the delimiter */ 254 memcpy(host, scopebuf, scopelen); 255 host[scopelen] = SCOPE_DELIMITER; 256 host[scopelen + 1 + numaddrlen] = '\0'; 257 #else 258 /* 259 * construct <numeric-addr><delim><scopeid> 260 */ 261 memcpy(host + numaddrlen + 1, scopebuf, 262 scopelen); 263 host[numaddrlen] = SCOPE_DELIMITER; 264 host[numaddrlen + 1 + scopelen] = '\0'; 265 #endif 266 } 267 } 268 #endif /* INET6 */ 269 } else { 270 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 271 h_error = h_errno; 272 273 if (hp) { 274 if (flags & NI_NOFQDN) { 275 p = strchr(hp->h_name, '.'); 276 if (p) *p = '\0'; 277 } 278 if (strlen(hp->h_name) > hostlen) { 279 return ENI_MEMORY; 280 } 281 strcpy(host, hp->h_name); 282 } else { 283 if (flags & NI_NAMEREQD) 284 return ENI_NOHOSTNAME; 285 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 286 == NULL) 287 return ENI_NOHOSTNAME; 288 if (strlen(numaddr) > hostlen) 289 return ENI_MEMORY; 290 strcpy(host, numaddr); 291 } 292 } 293 return SUCCESS; 294 } 295 296 #ifdef INET6 297 /* ARGSUSED */ 298 static char * 299 ip6_sa2str(sa6, buf, flags) 300 struct sockaddr_in6 *sa6; 301 char *buf; 302 int flags; 303 { 304 unsigned int ifindex = (unsigned int)sa6->sin6_scope_id; 305 struct in6_addr *a6 = &sa6->sin6_addr; 306 307 #ifdef notyet 308 if (flags & NI_NUMERICSCOPE) { 309 sprintf(buf, "%d", sa6->sin6_scope_id); 310 return(buf); 311 } 312 #endif 313 314 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) 315 return(if_indextoname(ifindex, buf)); 316 317 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 318 return(NULL); /* XXX */ 319 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 320 return(NULL); /* XXX */ 321 322 return(NULL); /* XXX */ 323 } 324 #endif 325
Indexes created Mon Sep 29 13:09:55 GMT 2025